Institut für Anorganische Chemie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellert ter 4, 1111, Budapest, Hungary.
Angew Chem Int Ed Engl. 2017 Jul 24;56(31):9231-9235. doi: 10.1002/anie.201704070. Epub 2017 Jun 28.
1,4-Diphosphinines that are fused to two thiourea units were synthesized from the corresponding tricyclic 1,4-dichloro-1,4-dihydro-1,4-diphosphinines, and their structures and spectroscopic features are described. Electrochemical studies revealed very low oxidation potentials, which are due to the effective π-interaction between the 1,4-diphosphinine ring and the orbitals of the two ylidic C=S bonds. In accordance with the low-lying LUMO, which is largely localized at the two phosphorus centers, dianion formation is strongly preferred. Despite the small HOMO-LUMO gap, which is in accordance with the red color of the title compounds, theoretical calculations suggest considerable aromaticity for the 1,4-diphosphinine ring.
合成了两个硫脲单元融合到一起的二磷杂环戊二烯，并描述了它们的结构和光谱特征。电化学研究表明，这些二磷杂环戊二烯的氧化还原电位非常低，这是由于 1,4-二磷杂环戊二烯环与两个亚甲酰基 C=S 键的轨道之间的有效π相互作用所致。根据主要定域在两个磷中心的低占据分子轨道（LUMO），二阴离子的形成是强烈优先的。尽管 HOMO-LUMO 能隙较小，这与标题化合物的红色相一致，但理论计算表明 1,4-二磷杂环戊二烯环具有相当大的芳香性。
